In the 1980s we downloaded games from the radio

This is great and I believe it. But saying your game would be loaded "after a few minutes" might be true for a small game. I had the Commodore 1541 floppy drive while my friend had the Commodore Datasette. The speed difference between these were huge. The floppy drive was around 300 bytes per second while the tape drive was around 50 bytes per second (3KB/minute). We would literally go outside to play while waiting on the tape drive.